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   1 /*
   2  * linux/arch/sh/boards/systemh/irq.c
   3  *
   4  * Copyright (C) 2000  Kazumoto Kojima
   5  *
   6  * Hitachi SystemH Support.
   7  *
   8  * Modified for 7751 SystemH by
   9  * Jonathan Short.
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/irq.h>
  14
  15 #include <linux/hdreg.h>
  16 #include <linux/ide.h>
  17 #include <asm/io.h>
  18 #include <asm/mach/7751systemh.h>
  19 #include <asm/smc37c93x.h>
  20
  21 /* address of external interrupt mask register
  22  * address must be set prior to use these (maybe in init_XXX_irq())
  23  * XXX : is it better to use .config than specifying it in code? */
  24 static unsigned long *systemh_irq_mask_register = (unsigned long *)0xB3F10004;
  25 static unsigned long *systemh_irq_request_register = (unsigned long *)0xB3F10000;
  26
  27 /* forward declaration */
  28 static unsigned int startup_systemh_irq(unsigned int irq);
  29 static void shutdown_systemh_irq(unsigned int irq);
  30 static void enable_systemh_irq(unsigned int irq);
  31 static void disable_systemh_irq(unsigned int irq);
  32 static void mask_and_ack_systemh(unsigned int);
  33 static void end_systemh_irq(unsigned int irq);
  34
  35 /* hw_interrupt_type */
  36 static struct hw_interrupt_type systemh_irq_type = {
  37         .typename = " SystemH Register",
  38         .startup = startup_systemh_irq,
  39         .shutdown = shutdown_systemh_irq,
  40         .enable = enable_systemh_irq,
  41         .disable = disable_systemh_irq,
  42         .ack = mask_and_ack_systemh,
  43         .end = end_systemh_irq
  44 };
  45
  46 static unsigned int startup_systemh_irq(unsigned int irq)
  47 {
  48         enable_systemh_irq(irq);
  49         return 0; /* never anything pending */
  50 }
  51
  52 static void shutdown_systemh_irq(unsigned int irq)
  53 {
  54         disable_systemh_irq(irq);
  55 }
  56
  57 static void disable_systemh_irq(unsigned int irq)
  58 {
  59         if (systemh_irq_mask_register) {
  60                 unsigned long flags;
  61                 unsigned long val, mask = 0x01 << 1;
  62
  63                 /* Clear the "irq"th bit in the mask and set it in the request */
  64                 local_irq_save(flags);
  65
  66                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  67                 val &= ~mask;
  68                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  69
  70                 val = ctrl_inl((unsigned long)systemh_irq_request_register);
  71                 val |= mask;
  72                 ctrl_outl(val, (unsigned long)systemh_irq_request_register);
  73
  74                 local_irq_restore(flags);
  75         }
  76 }
  77
  78 static void enable_systemh_irq(unsigned int irq)
  79 {
  80         if (systemh_irq_mask_register) {
  81                 unsigned long flags;
  82                 unsigned long val, mask = 0x01 << 1;
  83
  84                 /* Set "irq"th bit in the mask register */
  85                 local_irq_save(flags);
  86                 val = ctrl_inl((unsigned long)systemh_irq_mask_register);
  87                 val |= mask;
  88                 ctrl_outl(val, (unsigned long)systemh_irq_mask_register);
  89                 local_irq_restore(flags);
  90         }
  91 }
  92
  93 static void mask_and_ack_systemh(unsigned int irq)
  94 {
  95         disable_systemh_irq(irq);
  96 }
  97
  98 static void end_systemh_irq(unsigned int irq)
  99 {
 100         if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
 101                 enable_systemh_irq(irq);
 102 }
 103
 104 void make_systemh_irq(unsigned int irq)
 105 {
 106         disable_irq_nosync(irq);
 107         irq_desc[irq].chip = &systemh_irq_type;
 108         disable_systemh_irq(irq);
 109 }
 110